They settled on Alimango Island for a year. He became friends with - and had a crush on - Noritaka's assistant, a local girl called Shirley who was four years older than him. However, disaster struck when Shirley became a vampire after she drank a potion, intending for it to prove that Noritaka's research would save the world. She pled for Kiritsugu to kill her, but he refused and fled. Their village was overrun by Executors from the Church and Enforcers from the Association, both groups had arrived when they heard rumors of a magus researching into vampirism. Kiritsugu was the only survivor of the 'cleansing', saved by Natalia Kaminski, a freelancer and part-time Enforcer who wanted information on the magus responsible.

Returning to the hidden Emiya residence, Kiritsugu confronted his father on his research and Shirley's death. Norikata explained that he wanted to become a Dead Apostle to continue with his research on Magecraft longer. In the Fate/Zero novel version, just as Noritaka was planning their escape, Kiritsugu shot him in the back with a pistol; in the animated version Kiritsugu stabs Norikata with the dagger Kiritsugu received from Shirley and then shot his father, who was highly shocked at his son's betrayal, to death with a pistol that Kiritsugu found in Norikata's drawer. To this end, Natalia figured that the only person who could prevent Noritaka from escaping and ensure his death was his own son and she wound up taking Kiritsugu with her.

Realizing that the tragedies he saw in his childhood were common occurrences in the world, the teenage Kiritsugu became a freelancer like Natalia to hunt down heretical magi around the world. Natalia trained him not only in Magecraft, but in tracking, assassination, and all types of weaponry. At first, he only got in Natalia's way, but he eventually became her partner and equal.[4]

During one mission together, they were hunting down the last Zepter head Heinrich Zepter, who was a magus who mastered the revival of dead flesh. After tracking Zepter to an American village called "Present Mountain", Kiritsugu and Natalia discovered all two thousand members of the community were extensions of Zepter's body. They wound up destroying by throwing a hand grenade into the core of his body.

During the last mission together, Natalia was positioned aboard an Airbus A300 jumbo jet in flight in order to track a magus known as the “Demonic Bee User”, Odd Borzak. It was said that this magus successfully created Dead Apostles and could manipulate the Demonic Ghoul Bees under his control to use poisonous stings to increase the number of Ghouls under his power. The Ghoul Bees caused a fatal disturbance in the plane after the death of Borzak and began to infect all the passengers one by one until every single passenger had become a Ghoul. Kiritsugu, who was stationed at the plane's destination, elected to shoot down the plane after he deemed the situation too risky to allow the plane to land, sacrificing Natalia in the process. In their last conversation via radio, he admitted that she was like a mother to him. It was then that he became disillusioned with his ideal of becoming a 'hero of justice', as it was impossible to save one person without losing another. However, he continued to fight for this dream, to ensure that everything he had given up would not be in vain. He was eventually branded as the Magus Killer by the Association.

Around eleven years before the fourth Holy Grail War, he took on a younger soldier as his apprentice, who he eventually named Maiya Hisau, training her in much the same way Natalia trained him. She became his assistant in the field and also his 'lover', in a purely sexual context.

Two years later, Kiritsugu was hired by the Einzbern family to be their representative in the coming conflict. He entrusted all his equipment, including his Thompson Contender, to Maiya before leaving. Believing that the Holy Grail could grant his dream for world peace, he left behind his work as a 'hero of justice'.

He first met Irisviel von Einzbern in a tank when Justacheit von Einzbern made her. The Drama CD expands on how they met and their initial reaction. Kiritsugu questioned Acht as he viewed Irisviel as useless with no survival skills or defense abilities.

Acht took this personally and threw away Irisviel in the disposal yard during a blizzard as a test to determine her durability. Kiritsugu, disgusted, rushed to save Irisviel and took her back to the old von Einzbern castle. When she recovered, Kiritsugu decided to educate Irisviel about the current world with movies, pictures, and music. Gradually Irisviel became more eloquent and expressive, and she became interested in Kiritsugu himself. Despite Kiritsugu's initial hesitation, they eventually fell in love. However, Kiritsugu knew that love between the two would be fruitless, as he was aware that he would sacrifice her for the Holy Grail. For Kiritsugu's sake, Irisviel wanted to conceive a child so her husband would have hope after the Fourth Grail War. He was asked to marry into the Einzbern family.[4]

In his youth, Kiritsugu wished to be a Hero of Justice and protect the weak. He is often haunted by Shirley's question about what he wants to become, and how she believed him to have the ability to change the world. His hesitation to kill his first love when she became a Dead Apostle resulted in the death of the whole Island. Kiritsugu, realizing that his father was the cause of this and he would continue his Dead Apostle experiment, hardened his resolve and killed his father to prevent more deaths. Kiritsugu then resolved to make meaning and worth from the murder of his father. Only by hunting and assassinating all heretic magi like his father could he truly prevent such tragedies from occurring again. He lost all traces of youthful innocence after having spent his life going through countless battles while trying to obtain a utopia that could never be fulfilled, which caused him to become incredibly self-loathing. After finding out about the existence of the Grail, he sought to use it to obtain that utopia. He feels no emotion from personal victories over his targets, seeing them as nothing more than successful taunts with calculated resolutions.

In order to pursue his dream, he attempts to distance himself from his emotions, acting as the "machine that is Emiya Kiritsugu." He has managed to become completely devoted to any duty without showing any emotional wavering, though he is prone to occasionally fall into moments of extreme emotion and despair. When he admits that he is afraid and terrified of Kirei Kotomine, it is partly because of Kirei's bizarre personality, but also because of the fact that he fears that Kirei might be the one and only person who can kill him. When examining the Contender, he begins to wonder if he will remember the touch of his wife and daughter after the Grail War ends and falls into self-derision upon realizing the eight-year-old Ilya weighs less than a rifle. He dislikes such emotions interfering with his work, believing that his interactions with his family have made him more susceptible to sentimentalism in viewing the figures of his own wife and daughter in a passing mother holding her crying child.[5]

Kiritsugu tries to hold to the belief that there is no differentiation in sacrifice, that all life is equal and choosing the path leading to a smaller sacrifice is for the best. With a target that must be eliminated in order to save the world by obtaining the Grail, killing one thousand people to save at least five billion more should be easy for him. He finds himself unable to do so when planning to destroy the Hyatt hotel. He hates the idea of fatal romanticism like the hope that the innocent tenants will be able to escape the hotel in time impeding his abilities. Such ideas and sentiment would kill him on the battlefield, so he feels that he must rid himself of them as much as possible.

He has a close connection to Maiya that is older than the one with Irisviel, sharing a blood-stained existence not even his wife has ever seen. She acts to help balance his emotions, as she is often even more emotionless than him. Despite being close and having had a sexual relationship for a long duration of time, he shares no romantic feelings for her and attempts to simply regard her as a tool that will eventually die to serve her purpose. Because allowing his wife to sacrifice herself to complete the Grail is a betrayal towards her love, no matter what others say, it is necessary that he does not hesitate in this betrayal. Kiritsugu sees his sexual relationship with Maiya as a rehearsal before this betrayal, a form of self-abuse to steel his nerves while walking down this path.[6]

During the last moments of Maiya's life, he attempts to calmly tell her that she has nothing to worry about because her tasks are complete, and simply states "you will die here." He finds himself unable to speak, and instead, he almost finds himself crying for her. She eventually reminds him of his purpose and tells him to save his tears for Irisviel, allowing him to finally say, "Maiya, your task is complete."

He stopped smoking while with the Einzbern family but takes it up again during the Grail War: partly because he could not find his favorite brand, but mostly out of consideration for his wife and child. He instantly buys a pack out of habit and once again begins smoking as if it hadn’t been ten years. Being a Japanese native, he feels better while in the country despite being used to travel.

After rescuing Shirou, he found salvation in his despair. Before his death, he found a glimmer of hope as Shirou inherited his ideals and he believed Shirou to achieve this.[7] He once told a young Shirou that "boys who make a girl cry will end in ruins", something he experienced prior to his death.[8]

Overall, while Kiritsugu is a ruthless, calculating, stoic, emotionless, brooding, and cold-blooded killer who has committed some villainous acts to achieve his goals, he is idealistic and has good intentions which makes him mostly an anti-hero.

Kiritsugu treated Saber more as a tool than a person and disregarded her opinions. Their clashing ideals meant the two would never understand each other. According to Irisiviel, Kiritsugu accepted the fact that King Arthur was female and chose not to judge Saber based on her gender.

Kiritsugu saw Shirou as a symbol of hope that allowed Kiritsugu to believe he had not abandoned everything for nothing, as he was still able to save one boy at the end of the Fourth Holy Grail War. Kiritsugu initially wanted to raise Shirou as a normal boy, but he was convinced to teach Shirou basic magecraft and died believing Shirou could actually fulfill his own life-long dream of becoming a "Hero of Justice."

Despite being the true Master for Einzbern family, Kiritsugu operated mostly in the background during the conflict, ambushing other Masters when they were otherwise occupied, while Saber, who was summoned using Excalibur's lost sheath as a catalyst, was partnered with Irisviel and made to act out in the open. This was to avoid conflict between Kiritsugu and Saber, as the methodologies of the two conflicted with each other too much. Saber and Irisviel traveled from Einzbern's castle in northern Europe to Japan by plane, while Kiritsugu took a different route, entering Fuyuki by ship and meeting with Maiya.

Kiritsugu rejects 'Irisviel'

In the climax of the war, Kiritsugu fought the last Master, Kirei Kotomine to a standstill, both being consumed by the black 'mud' flowing out from the Holy Grail. There, Kiritsugu met 'Irisviel' again, now completely merged with the Grail. In his mind, he was forced to confront the fact that his methods will eventually lead to him becoming the ultimate enemy of humanity, equal to Angra Mainyu itself - and, 'Irisviel' proclaimed, this path is correct. Kiritsugu, rejected the Grail's argument saying that he sought the Grail because his own methods are insufficient to bring about the utopia he sought, only to have the Grail argue further that it cannot grant a wish without a methodology to realizing it. In other words, the Grail only sought to grant his wish by doing what he has always done in his stead. Now realizing that the Grail was corrupted and false, Kiritsugu rejected 'Irisviel', who placed a curse on him - to never be free of regret until his painful death. Kirei, having gone through the same experience, asked Kiritsugu why he rejected the Grail; Kiritsugu killed him after a vague response.

Kiritsugu using his remaining Command Seals to order Saber to destroy the Grail.

Kiritsugu appeared during the final battle between Archer and Saber and, without explaining what he just found, used all his remaining command seals to force Saber to destroy the Grail with Excalibur, causing her to fade away. However, Kiritsugu realized immediately after that this was a mistake - by leaving the Greater Grail intact, 'mud' from its core was able to spill onto the streets below, causing a fire that eventually destroyed a large part of Shinto.

Shirou being rescued by Kiritsugu.

With the war's end, Kiritsugu discarded his merciless facade and sought to atone for his gruesome deeds. When he stumbled upon a dying Shirou, seemingly the only survivor after the fire, he was overjoyed at the opportunity to save a life. In order to revive him, Kiritsugu implanted Avalon into Shirou's body. Kiritsugu later adopted him as a son, settling in the new Emiya residence that he purchased during the war.

He met Taiga Fujimura sometime after, and due to her resemblance to his first love, Shirley, he doted on her a great deal.[9]

Once Shirou was old enough, Kiritsugu left Fuyuki several times, traveling back to the old von Einzbern castle, trying to see his daughter. However, he never managed to find his way past the bounded fields, having lost most of his magecraft abilities. After his betrayal, rather than seeking to punish him, Jubstacheit von Einzbern never again allows Kiritsugu into their Bounded Field and keeps him away from his daughter, who is raised by Acht under the impression that she was abandoned by her father. Kiritsugu believes that Acht either wishes to exile him to carry the deplorable status of traitor for the rest of his life or to impose the most severe punishment that can be inflicted by never allowing him to see his daughter again.

To ensure the destruction of the Great Grail, Kiritsugu used explosives to create a 'bump' in the nearby leyline, which would ensure an earthquake in thirty to forty years' time. By doing so he hoped to prevent a fifth war, but did not realize that the incomplete ending of the fourth war would cause the next war to occur in just ten years.

In the Drama CD, Kiritsugu was awake late at night and Shirou woke up after experiencing nightmares from fire. Shirou would take the medicine that Kiritsugu made with magecraft. Shirou asks Kiritsugu about teaching him magecraft but Kiritsugu was completely against it. The next day, he sparred with Taiga in kendo and complimenting her for her skills. Kiritsugu asked for Taiga's advice and her answer helped his decision about teaching magecraft to Shirou.

Angra Mainyu's curse eventually cost his life, as his limbs were lame, his sight failed, and most of his circuits became useless. His last moments were with Shirou, watching the moon outside his garden. It would be his happiest memory, during which he reminisced on his life, noting that it was full of regrets especially his inability to save his daughter. Revealing his childhood dream to Shirou about becoming a 'hero of Justice', Kiritsugu admitted that the dream was impossible to accomplish as he became an adult. Shirou, who looked up to Kiritsugu, hated the way he spoke of his weakness and reassured Kiritsugu that he can accomplish it as he was still a child in Kiritsugu's place.

Kiritsugu's final moments

He died peacefully as he vaguely stared at the moon and commented on how beautiful it is. He died at the age of thirty-four, five years after the end of the War, passing onto Shirou his ideal of a 'hero of justice'. In his last thoughts, he recalled when Shirley asked what kind of adult he wants to become and he had said:

« I'll never forget what I felt today. I want to be a hero of justice! »

Although he died before Fate/stay night, he is referenced by many characters. He is buried in the graveyard behind Ryuudou Temple, though Shirou rarely visits. His death left Shirou frustrated, depressed, and alone.

Shirou frequently recalls how Kiritsugu saved him and how Kiritsugu had offered to adopt him, along with revealing that he was a magus. When Shirou expressed interest in learning Magecraft, Kiritsugu disapproved and initially refused until Shirou's persistence wore him down. Advising that Magecraft should only be used in secret and to the benefit of others, without attracting suspicion or confusion, he taught Shirou very basic and incomplete knowledge of sorcery. However, this knowledge would lead him down a dangerous path with little results.

Before dying, Kiritsugu had revealed to Shirou how he once strove to become a "Hero of Justice" - a person who could save everyone - but gave up once he realized it was impossible, citing it was a dream that could not be achieved by an adult. However, Shirou took the ideal as his own, promising to accomplish it in Kiritsugu's stead. Archer generally disapproves of the ideal; in the Unlimited Blade Works scenario, it is revealed that Archer is a possible future incarnation of Shirou where he regretted the path he took. Archer's memories are incomplete, but he remembers certain events, one of the important events he remembered being when Kiritsugu saved his life after the fire. He understood Kiritsugu's last words and experienced the same suffering that Kiritsugu had. In his duel against Shirou, he claims that his ideals are borrowed and he simply admired Kiritsugu because he saved him.

During the Fifth Holy Grail War, in the Fate and Heaven's Feel scenarios, Shirou discovers that his father was a master of the Fourth Grail War, and Saber's original master. In both routes, Saber revealed to Shirou that Kiritsugu was her Master in the Fourth Grail War. Furthermore, she is stunned into disbelief when she observes how Kiritsugu was an entirely different person in Shirou's memories. In the Fate scenario, she wants to know why Kiritsugu betrayed her until Kirei Kotomine reveals that the Grail was tainted. Finally understanding why Kiritsugu destroyed the Grail, she eventually accepts and agrees with her former Master's actions. Saber also expresses gratitude toward Kiritsugu for implanting Avalon in Shirou, which saved his life on many occasions, first when Berserker attacked Shirou and when Kirei heavily injured him. In the Heaven's Feel scenario, she discovers why Kiritsugu betrayed her after being corrupted by the ichor of the Grail.

Upon her entry into the war, Illyasviel von Einzbern specifically targets Shirou because of his connection to Kiritsugu. Believing that Shirou had stolen her father and that Kiritsugu had abandoned her mother to die in the Fourth Grail War, she attempts to fulfill the Einzbern's desire to revive the Third Magic and avenge their defeat after Kiritsugu's betrayal. In the Heaven's Feel scenario, after being kidnapped by Dark Sakura and informed about Avenger and the corruption of the Holy Grail, she admits that Kiritsugu was correct in his decision to destroy the Grail.

When Kotomine first meets Shirou, his interest is piqued because Shirou shares the same surname as Kiritsugu. In the Fate and Heaven's Feel routes, he revealed everything about his deeds during the Fourth Grail War. In the former scenario, Kotomine used the power of Angra Mainyu to curse Shirou just like Kiritsugu.

Kiritsugu makes no appearances in Fate/hollow ataraxia, though it is common knowledge that Illyasviel is Kiritsugu's daughter. Taiga often requests that Shirou take her to visit Kiritsugu's grave.

He has a brief appearance in Carnival Phantasm, celebrating with his family Irisviel and Illya in Ahnenerbe at the end of the carnival.

He does not appear in Capsule Servant game. He kidnapped Irisviel from the Einzbern and married her, he adopted Shirou during in his business trip. In the events of Capsule Servant, he is on an overseas business trip with Irisviel.

Kiritsugu appears in the 6th episode of Today's Menu for Emiya Family, a flashback episode which details the first time Shirou cooked hamburgers for him.

He also makes an appearance in one chapter of All Around Type-Moon in which he encounters his former Servant Saber, yet he fails to recognize her. At one point, he brushes past Archer when leaving. Archer is surprised, but is happy to be able to see his father one last time.

Kiritsugu, due to the lack of devoted magecraft training under his father or Natalia, is only average as a magus, and instead specializes as a "Magus Killer." He has a number of specialties that would not make him very notable within the Mage's Association, but instead make him useful for higher-ups when they need an assassin to kill other heretical magi. Compared to someone like Rin Tohsaka, who would have a high numerical value as a magus, Kiritsugu would have a low value as a magus, but a much higher evaluation as a specialist.[10]

His relationship with the Association is much like how the Church treats its Executors. His abilities are great enough that even the Church considers him to be "an individual that requires surveillance." He is noted for many cases of missing persons and accidents believed to be magi he has killed, and many tragedies of the past reported as major acts of terrorism are in reality criminal acts committed for the sake of killing one magus. While there is no actual evidence, events such as planting a bomb in public and striking down an airplane with many passengers on board are believed to be caused by him.

After becoming cursed by Angra Mainyu, he slowly deteriorates over a number of years as his flesh keeps growing weaker, his limbs become atrophied, and he completely loses the ability to use magecraft. He becomes unable to even find the starting point of the Bounded Field of the Einzbern Castle, while the “Magus Killer” would have been able to forcibly break through, he is left to wander in a blizzard without any hope of finding it. Once he fully succumbs to the curse, he dies peacefully.

Kiritsugu is a very unconventional magus, known as a Spellcaster, that treats magecraft as a mere tool in which he has acquired knowledge rather than the object of his lifelong goals, and he primarily prefers the use of modern technology supplemented with any little magecraft abilities he has to gain an advantage over enemies. Compared to someone like Tokiomi Tohsaka, who refuses to use phones and the like despite their convenience, he freely uses anything at his disposal in order to accomplish his goals. He learned most of his skills from studying Natalia's abilities while also refining his own as her assistant in his pursuit to become a "hunter" that stops other heretical magi like his father. Much of his ability comes from the fact that he can act cold and ruthless to complete his objectives. After having spent time in retirement with his wife and daughter, he believes he has degraded a great deal compared to the Emiya Kiritsugu from nine years before. He is no longer as willing or capable of being as ruthless as he once was due to his interactions with them, which he believes he needs to change. He wishes to restore his cold manner of judgement as fast as possible in order to be able to obtain the Grail.

He developed his skills working as a Sealing Designation Enforcer for a number of years, learning methods of tracking, assassination, the usage of various weapons, and other skills needed to be able to catch up to his prey under all situations and conditions and bring it down. He sought to have his body master the skill of "killing people" that humans have spent an endless amount of time and intelligence to research. He is very skilled with using numerous blasting techniques from the past to the present, and he feels a certain appreciation for the certain art of destruction. He uses C4 combined with a precision blasting demolition technique used primarily to demolish tall buildings, allowing him to destroy the Hyatt hotel with a minimum amount of explosives. With the blueprints and planning, it only takes him an hour execute the entire plan. Targeting the load-bearing walls and key support structures, it collapses downward and inward on its own weight without much debris spilling onto the surrounding streets and causing unnecessary collateral damage.

He is very familiar with the workings of Magic Circuits and the related temperature changes in the body of the practitioner. Having trained and studied the correlation, he is able to read the current status of the Magic Circuits through the heat distribution of the practitioner when viewed on the thermal output of a heat detecting scope. He is able to tell the difference between an ordinary person and a magus, allowing him to seize an opportunity to shoot upon the release of magical energy. Compared to magecraft, which can see through the dark better and detect the position of an enemy magus, it can be said guns fall behind. Its advantage is that it takes no magical energy to use firearms, leaving a magus unsuited to the battle conditions of a soldier trapped in the dark and unable to detect any magical energy.

He is extremely skilled in penetrating Bounded Fields, allowing him to break through the Tohsaka residence's strong bounded field in three hours. It is an almost miraculous method allowing him to overcome a first-rate security system specifically guarding against magi that wouldn't be broken even if attacked continuously for a whole year by magecraft. Due to it being created with magi in mind, he was able to overcome it precisely because he is someone who does not seek results by way of magecraft and from his experience in fighting against magi by perceiving traps wrought through magecraft. He supplements familiars with miniature CCD camera tied on the abdomen as a measure of recording the true nature of the area. There are often illusions and camouflaged bounded fields based on using suggestions on an observer, but most magi would never develop countermeasures for electronic-based threats. Even though it slows the familiar's speed, it is also useful to have video records to rewatch events at a later time or show them to others.

Kiritsugu has the mindset of a skilled assassin, and rather than facing another magus in a direct duel of abilities, such as in a battle between their Mystic Code's; he makes use of various plans, traps, and schemes that utilize both magecraft and modern weaponry in order to take out his targets. He preys on the weak point of magi, their negligence derived from arrogance; which makes them believe that the only true threat to them cannot be anything other than a magus of similar skill. He relies on the fact that a self-conscious magus, having stepped into a world of mysteries beyond human intellect, is unable to relate to the stereotypes of a narrower world; such as the conditions of a battlefield or scenarios, the type a regular soldier may face. He follows the methodology that the attack the enemy does not expect is a shortcut for all battles; and preys on the fact that they constantly stay on alert to the slightest trace of magecraft.

Kiritsugu attacking the hotel

Magi generally only hone their skills, counter measures towards thaumaturgical threats; ignoring any attack that is purely physical, and void of magecraft. They view the sharpest knives and strongest bullets as secondary menaces they have no need to fear. Before such an attack actually pierces their flesh, they are confident in their illusions, paralysis methods; and defensive bounded fields being more than capable to negate such attacks. They despise technology and underestimate what a human without magecraft can accomplish, which makes them weak to non-magical attacks from Kiritsugu. Though most magi would take the idea of entering the lair of another magus as a challenge, Kiritsugu takes an opposite approach. When faced with the Hyatt hotel; Kayneth's stronghold, which has been fortified with magical furnaces, spirits and apparitions, and a large Bounded Field; Kiritsugu decides to destroy the entire building instead of mounting a direct offensive against the defenses inside. With as much pride Kayneth has as a magus, he is willing to stay inside, believing with all certainty that Kiritsugu will invade rather than giving any thought that his entire castle will be destroyed instead.

Not only is Kiritsugu able to dispatch most magi with his magecraft enhanced modern weaponry, but even in some special cases he calls "formidable enemies", he is still able to once again follow the methodology that technology is a blind spot to most magi to easily overcome many of them by night vision and a heat sensor scope. However, most magi will not deviate from that generality; there exist those that are impossible to measure with rules and experience. Against those who Kiritsugu's normal strategies will not prevail against, he must act as a magus and use his Mystic Code, which is his most powerful weapon. Even facing such an opponent, he is extremely adept at forming strategies and analyzing enemy movements and their magecraft, performing well even under tremendous stress from active combat. Within just one encounter with Kayneth's Mystic Code, he is able to find three weaknesses, form a countermeasure against it, and plan for his final assault.

Kiritsugu is able to work in tandem with multiple parties, but he regards those people simply as "tools" to further his goals. His relationship with Maiya Hisau is that of a pupil and a teacher, but due to viewing magecraft as a tool, there isn’t a single sense of master and pupil between them. He has only taught her a “way to fight” so that he may also freely use her as a “tool.” She acts as a vanguard scout, and due to years of working together, they are very in sync with each other's actions. She is a "supporting machine" whose actions are even more akin to a machine than those of the machine called Emiya Kiritsugu, and an " indispensable final weapon" to help him win the battle. Out of all of his teachings, she is most skilled with using bat familiars supplemented with cameras, and she makes use of a Steyr AUG assault rifle with a replaced night vision scope while still remaining under five kilograms. She is more of a soldier than a direct combatant, so he generally trusts her with reconnaissance and scouting due to her skills with familiars, and he allows her to procure all of his equipment.

They have exchanged strands of hair between them, which Kiritsugu used as the basis for a spell in order to act as a measure indicating the worst-case scenario in which it has become impossible to use a wireless network or familiar to convey information. The enchanted strands were embedded in the subcutaneous tissue of their pinky fingers with the purpose of sensing if the Magic Circuits of one of them entered a state of extreme stagnation, the stage at which one's life force was weak on the verge of impasse with death. If the hair embedded in either one of their fingers starts to burn, it is a warning to notify them of the existence of danger, and it really essentially acts only as a signal to inform that "it is already too late."

He follows the methodology that Servants are the tools of their Masters, and that no matter how famous the hero, they will be nothing more than that as long as they are summoned as a Servant. Despite Saber being one of the most powerful Servants of the Saber class, he finds that Assassin or Caster would suit his style of combat more appropriately. Due to Saber's chivalrous preference for direct confrontations and fair battles, it is hard for him to coordinate with her. He instead has Irisviel pretend to act as Saber's Master, while he acts from the shadows. They only speak a few times in total, and are unable to ever agree with each other's methodology.

Kiritsugu lacks the various ritualistic catalysts used by normal magi like a dagger, cup, talisman, elixir, or spiritual container. He instead uses all state of the art weaponry that are unable to store any magical energy, which is the "heresy" that earned him his title. He utilizes a large number of different firearms and weapons to kill his targets and is extremely skilled with all those weapons. He also makes use of personal hand grenades, stun grenades, smoke grenades, C2 plastic explosives, and landmines, and he is skilled in incorporating them into traps with trip wires, hidden fuses, and a detonation system using a cellphone to trigger them through modified communication loops. He has number of Claymores, which simultaneously release around seven hundred steel balls with diameters of only one or two millimeters. They radiate outward in all directions in a fan formation with enough power to destroy an infantry unit in one strike. He is also familiar with setting up surveillance systems, allowing him to use a number of concealed CCD cameras throughout the Einzbern castle.

He also has specialized magical equipment, such as an eye drop bottle filled with a liquid made from refining the body fluids of a succubus. It is sensitive to the blood of men and aged things, allowing it to immediately identify such substances. It is capable of comparing substances and distinguish differences accurately, allowing him to compare left over residue from shaving to a bloodstain to identify both as being left by Tokiomi.

Avalon, Saber's Noble Phantasm, is placed in his possession by Acht in order to be used a summoning catalyst. Rather than allowing Saber to have it, he hides its existence from her and keeps it for his own use. Normally, it would be used as the trump card of Kiritsugu as Saber's Master, but he is not present on the direct battlefield. It is a useless tool to him due to that Saber would not be able to provide it with magical energy since he is working so far apart from her. He leaves it for Irisviel's protection due to her acting as the front line substitute Master for most of the Grail War. Once returned to him, he seals it inside himself as a Conceptual Weapon and makes use of the contract with Saber to provide the full effects of its immortality. It revives him after his heart and lungs are completely destroyed by completely healing him seconds before his blood-deprived brain is about to die due to lack of oxygen. Even he is surprised with its potency, and decides to work it into his battle strategy to counter the negative effects of Innate Time Control. While it can heal both injuries caused by enemies and damage dealt to himself, it only nullifies the damage without taking away his pain.

The state coupled with his Innate Time Control could allow him to defeat a Servant under limited conditions. The only ones he could readily defeat would be those who lack physical power like an Assassin after having been revealed or a Caster in close combat. Defeating those that specialize in hand-to-hand combat would require a special condition in his favor like surprise or suitability against the opponent.[11]

The Calico M950 (キャリコM950, Kyariko M950?) is a submachine gun used by Kiritsugu and Maiya as a reserve sidearm. It has a compact size similar to a large handgun with a reinforced plastic that makes it look more like a toy when compared to the Walther. It has a unique helical-feed magazine that allows for fifty Parabellum rounds to be fired at a rate of seven hundred rounds per minute. It is also equipped with a sound suppressor, laser sight, and vertical foregrip.[12]

The Thompson Contender (トンプソン・コンテンダー, Tonpuson Kontendā?), also called the Thompson/Center Arms Contender Custom (トンプソンセンターアームズ・コンテンダー, Tonpuson Sentā Āmuzu Kontendā?), is a special piece of equipment compared to his other weapons, which are armaments for the Magus Killer that can simply be bought and replaced at any time.[13] It is something that cannot be bought with money that represents Kiritsugu as a magus, a Mystic Code with which he can use magecraft during battle against another magus. It is a one of a kind weapon only for his use that he has favored on many battlefields. It is used in conjunction with Origin Bullets (起源弾, Kigen-dan?), which are special Conceptual Weapons that utilize Kiritsugu's Origin to its fullest extent by actualizing it within a target. The bullets were created from his first and second ribs on both sides being cut off, extracted from his body, ground into dust, condensed with a craft to preserve his soul, and sealed within sixty-six bullets as their core. The gun and bullets are stored within a rosewood case, which was left with in the care of Maiya during his nine years of retirement. It is 444 mm long and in its base form weights 1700g, with his modifications bringing the total weight to 2060g.

Kiritsugu using the Contender

The Contender was developed in 1967 by American company Thompson/Center Arms. It is a break-open single-shot pistol meant for sport shooting. Simple yet powerful, the weapon can, with little modification, be used to shoot various ammunition ranging from .22 LR to rifle bullets. While it is not suited for real combat, it was chosen as his Mystic Code due to it being able to deal the maximum physical damage possible. Its grip and forearm are carved in walnut, making it reminiscent of a dagger in its scabbard. The only visible mechanical parts are the trigger and the hammer, with neither a cylinder nor a slide on the simple exterior, making it similar to the percussion pistols used in the last hours of the Middle Ages. The lack of complex parts between the barrel and trigger allows for high accuracy. Kiritsugu's is customized with a fourteen-inch rifled barrel made for hunting specifications and fitted for .30-06 Springfield bullets. The cartridge of the bullet has a bottleneck structure, and its size and power level on an entirely different level from a handgun bullet. The .30-06 is 10% stronger than the .308 Winchester rifle bullet, and even surpasses the hand cannon class of a Magnum bullet.

While it is a powerful weapon with especially powerful bullets displaying destructive power capable of easily puncturing bulletproof vests and killing large animals in a single shot when discharged from a handgun, its true use lies in the specialized firing pin and additional magical modifications for firing the Origin Bullets. Origin Bullets, containing part of Kiritsugu's soul, actualize his Origin of "Severing and Binding" upon contact with the target, which can cripple living creatures that are fired upon. There are no wounds or bleeding upon the bullet making contact, but the targeted area or body part appears to be suffering from necrosis. While it seems to have healed properly on the surface, the nerves and capillaries will never regenerate properly and the original function will be forever lost. While it would be bad for a living being to be hit by it, as a Conceptual Weapon, this bullet poses an even graver threat to magi in particular. Out of the sixty-six Bullets, thirty-seven bullets have been used, and not a single one was wasted after completely destroying thirty-seven magi. During the Grail War, he has access to twelve bullets, and Kayneth becomes the victim of the thirty-eighth bullet. The only person to render it ineffective is Kotomine due to the fact that he doesn't fight like an orthodox magus.

Origin Bullets

Origin Bullets will immediately affect magi upon coming in contact with their magecraft. The only practical way for magi to defend against one is to discard all magecraft and defend purely by physical means, but he uses a particularly malicious method forcing the use of magecraft by making it impossible to physically block it. The bullets excel in penetration, and there is little outside of magecraft capable of blocking the specialized hunting rifle unless they are protected by the military-grade armor of an armored vehicle. Being forced to defend with magecraft, the impact of the Origin within the bullet affects everything all the way down to the Magic Circuits of the practitioner. If a magus' Circuits are a high-voltage power cable, then the impact of the bullet is comparatively a drop of water attaching itself to a thickly-placed electrical circuit. Once a conductive liquid becomes attached, the short-circuiting current will destroy the circuit itself, resulting in permanent damage.

The more intense the pressure used to gather densely-packed magical energy for defense, the more active Magic Circuits will be functioning upon the moment of contact, and the more severe the destructive power of the bullet becomes. With an RPG analogy, it can likened to an attack that converts the MP of the user into damage, so someone with a high amount of MP compared to their HP would be overwhelmed and someone with a low amount of MP to their HP would only receive a small amount of damage.[14] The "Severing" aspect will cause magical energy stored within the Circuits to ignore the paths within the body, flowing chaotically and destroying it in the process. Afterward, the circuits will be bound together again with the "Binding" aspect, albeit in a chaotic and useless manner, thus rendering them permanently inoperable and destroying the target's magecraft abilities. If used against a magus not actively using their Magic Circuits, such as Kotomine supplementing his own abilities with Command Spells instead of his own undeveloped Magic Circuits, it will target the source of the abilities instead. Targeting the one-use seal, it simply dissipates after being struck by the bullet without affecting Kotomine.

Kiritsugu initially uses normal .30-06 Springfield bullets in order provoke the enemy into believing that those are his strongest weapons. Utilizing the bullets that have an initial velocity 2.5 times higher than 9mm bullets used by his Calico and seven times the destructive power, they become focused upon making sure that they can consciously defend against such an attack and focus most of their magical energy towards that task. When someone is provoked into using their utmost amount of magical energy, the damage is completely fatal. It causes excruciating pain within the body as the nervous system spasms while being broken down. Their internal organs are almost destroyed, and numerous muscles and nerves are damaged. If they do not die instantly, the wounds will quickly prove fatal, and even if healed by a magus, it would be impossible to recover enough to even stand again. Once Kayneth is struck, it takes a great deal of money and an expert puppet master to simply get his hands working enough to move a wheelchair.[15][16]

The Walther WA2000 (ワルサーWA2000, Warusā WA2000?) is a super heavyweight, semi-automatic sniper rifle of the highest class and performance that is the pinnacle of the latest electronic techniques. It costs $12,000 due to only being one of the 176 units produced. It is a rifle with a compact size measuring a little over ninety centimeters in length with the bullpup structure of the gun barrel with a gas-operated magazine measuring at a length of sixty-five centimeters. It fires a .300 Winchester Magnum cartridge that has an effective range of up to one thousand meters. While it is not equipped with its standard Schmidt & Bender telescopic sighting device, Kiritsugu has installed a pair of extra-large electronic optic devices as a special scope mount fixed in parallel above the barrel and on the left flank.

The unit on the main side is the AN/PVS-4, the latest night vision scope used by the US armed forces that has been banned from being exported to prevent the leaking of technology to other countries. It uses a super sensitive video camera that acts as a light electrical amplifier with a lens, raising and displaying a perfect brightness. Acting as an electronic "owl eye", it multiplies the range of vision by 3.6×, allowing it to view up to six hundred meters under the moonlight or four hundred meters in starlight. The second unit is an Elcan Specter IR thermal weapon scope installed as sideways support. It is also electronically equipped for night vision, but displays the subject's heat pattern on the image display rather than acting as an intensity amplifier. It can perceive temperature variations from -5 to 60 °C up to two hundred meters with an 1.8× magnification.

The scopes are large and bulky, both being the size of plastic bottles and giving the relatively compact gun an air of unbalance, which brings the total weight of the gun to over ten kilos. Even with the steady progress of miniaturization, they are still large even compared to standard optic devices. It is a weapon more suited to a support fire squad more than a sniping weapon, and its practical use is hindered. Despite the challenge, it was within his calculations in best managing to make use of the weapon. The joint use of both scopes allows him not only the ability to fight in darkness, but they have also been configured to allow him to face off against a magus. Sensing the Magic Circuits within the dark, it can fire upon them from hundreds of meters away without them being able to detect him at all.[17]

The Emiya Magic Crest is carved on Kiritsugu's back, but he was unable to inherit it properly from his father as a normal magus. Due to the Sealing Designation, Noritaka's body was retained by the Association, and all the important parts of the Crest were confiscated. Through Natalia's negotiations, Kiritsugu was allowed to inherit part of the Crest, but it was only a "fragment" that contained less than half of the original amount. It was enough that he was able to use his abilities as a magus, but he had little interest in continuing the research in the first place. His only interest was whether it would prove practical as a tool in combat situations. While he relies on modern technology, he is still capable of using various different spells and techniques in his work. He is capable of using night sight by focusing magical energy to his eyes, allowing him to instantly see with impeccable clarity in the dark. He is proficient in using familiars, and he has taught Maiya how to use them as well. He can use basic hypnotic suggestions on those with no natural resistance to magecraft by making the target focus on his eyes.

Kiritsugu's Elemental Affinity is the dual attributes of Fire and Earth, and as composite attributes, they are linked to his dual Origins, Severing and Binding (「切断」と「結合」, "Setsudan" to "Ketsugō"?). The previous generation of the Emiya family was at a loss upon finding the nature of his Origin, and named him Kiritsugu due to the strange results. Severing and Binding is different from the idea of "destruction and rebirth." There is no chance of "recovery" in the case of binding, such as a string being cut and connected back together by tying the two pieces. While it is once again whole, there is forever an irreversible "corruption" in the form of a change in thickness where the knot it tied. It takes form in his everyday life when doing hands-on work, which caused him to become particularly aware of his Origin. While he can fix normal contraptions, he is unskilled in working with delicate machinery. His unskilled hands suddenly cause everything to become the opposite, and the more he wants to fix something, the worse the damage becomes for the machine. He can use handcraft to piece together a snapped metal wire while still restoring the original function, but fixing a delicate electric circuit using the same principles will have fatal results. It is not something that will work as long as everything is connected, and if the connections are out of order, the circuit will lose its function. Rather than being caused by his personality or temperament, it is the true essence of the root deep within his soul.

Innate Time Control (固有時制御, Koyū jiseigyo?) is Kiritsugu's personal application of the Emiya family's magecraft. They spent generations researching and seeking the magecraft that controls time, eventually reaching "Time Manipulation", which is the ability to separate the passage of time inside a designated space from the "flow of time" in the outside world. It is classified as High-Thaumaturgy in the form of a Bounded Field that can be regarded as a type of Reality Marble in a way, but still not something extraordinarily difficult to utilize like other time related magecraft or something on the level of the True Magic that is unable to be replicated. It allows for "time adjustment" that can only stagnate the time which has passed and accelerate time in the future rather than something more advanced like "time modification", which has the ability to reverse cause and effect and change the past. The major problem is that the practitioner needs to consider the size of the Bounded Field and the scope of time that needs to be modified. It requires a large amount of magical energy and similar rituals in the same magnitude of High-Thaumaturgy to activate it. It would normally be applied to a wide area and a long period of time, taking longer to set up and more magical energy to utilize it as the Bounded Field becomes larger and the deviation in time becomes longer.

It is not an ability that can be used on the battlefield where strategies must be quickly made in order to survive, as it must be prepared beforehand and used strategically even after the preparations. The Magic Crest of the Emiya family contains generations of inherited research, but that is unimportant to Kiritsugu. It was a useless inheritance until he found a way to use it to its maximum potential in a combat situation. He worked around the issue of size and magical energy consumption by creating a flexible method of utilizing it on a small scale that only applies to himself. This allows for the establishment of the Reality Marble at any given time without the need of extended rituals. It is impossible to completely isolate the flesh from the outside world, but the ability can minimize the effect the outside world has on the body. Keeping the scope of the spell to a minimal bounded field within his own body, it doesn't allow for the world to be affected, but rather allows for Kiritsugu to "adjust" a few seconds of time within his own body. He uses the chant Time alter (固有時制御, Koyūji seigyo?), followed by the degree of speed he wishes to use. The chant accel (速, soku?) allows him to speed up, while stagnate (停滞, teitai?) slows him down. He can use Release alter (制御解除, Seigyo kaijo?) to stop it an any point.

Time alter - double accel

Time alter - double accel (固有時制御二倍速, Koyūji seigyo nibai soku?) is his most used version, allowing him to move faster than the human eye can see. It speeds up his blood flow, hemoglobin metabolism, and muscle movement all at the same time. Using this brief burst of speed, he can use his own physical skills and reaction speed at a level far above human limitations. It allows for split second evasion in front of an enemy, and its power of mobility can make for one of his greatest defenses. Normally double accel is enough to push his body past its limits with brief use, but with Avalon providing regeneration, he is capable of using Time alter - triple accel (固有時制御三倍速, Koyūji seigyo sanbai soku?) and the quadruple-accelerated time of Time alter - square accel (固有時制御四倍速, Koyūji seigyo yonbai soku?) for an extended period of time. Using stagnate, he can slow his biological processes, and using Time alter - triple stagnate (固有時制御三重停滞, Koyūji seigyo sanjū teitai?) reduces them to one third of their normal speed, slowing his heartbeat to the point where he can barely feel it himself, slowing his breathing so it lags, and reducing his metabolism to the point where body temperature cools quickly enough to almost match room temperature. The sound of his presence is reduced enough that Volumen Hydrargyrum is unable to make out his breathing and heartbeat from the other noises in the natural world, and it is unable to recognize him by using the standards of a human. While there are not any changes within the actual world, his optic nerves and eardrums register what he sees and hears from within the bounded field. His cornea receive three times the light a person's eyes normally receive, which makes his field of view extremely bright, and his hearing is dulled.

Even with his minimalistic approach, it is still High Thaumaturgy far above the level of basic physical enchantment that causes inconsistencies between the flow of time inside and outside the field. Once the movement is complete and the field is removed, natural forces, the "world’s own adjustment", will forcefully adjust the "incorrect time." This places a large burden on Kiritsugu with each use, as the bounded field where the "errors have occurred" is within his own physical body. In order to get back in sync with the normal time flow, adjustments occurring within his flesh greatly damage him. Even brief use has him accompanying death, and continuous activation is nothing less than suicide, making it his riskiest technique. When returning to normal from stagnating, he suffers from the blood flow speeding up back to original speed, which causes burst capillaries and internal bleeding. Without the use of Avalon, Double Accel is his limit when speeding up, and even a few seconds of it is enough to rupture numerous blood vessels and cause fractures in the bones of his limbs due to the burden. Provided with constant regeneration from Avalon, he makes use of the ability's purpose as a strategic weapon to its full potential by utilizing higher levels while enduring his body breaking down and healing at an extremely high rate. He still feels the torn tendons and snapping bones tormenting his nerves while shedding mists of blood with every movement, but the regeneration allows him to keep fighting with accelerated speed for a much longer duration of time.

Takashi Takeuchi feels that the young Kiritsugu looks like the protagonist of a shonen manga. While he was the protagonist of Fate/Zero, he is lacking in artwork compared to other characters, as he only appeared on the cover twice. One shot was from the back, while the other was only a silhouette. Gen Urobuchi felt that, because he abstains from the flashiness of Heroic Spirits, the best solution was to make him unnoticeable, as a "character who spreads justice should speak with their back.[1]

Despite his shadiness, he still uses boku (僕?), a first person pronoun most generally used by young boys. It was part of Nasu's design of the character, as Urobuchi felt he could never come up with it.[1]

Tomonori Sudo was in charge of Kiritsugu's character design for the anime version. He first thought Kiritsugu was a character who was not capable of expressing much emotion. Since he's a character with the strength to blot that out, it was a difficult thing to bring out the side of him that's rather frail and weak in comparison to his hard exterior.[4]

When Rikiya Koyama first played Kiritsugu in Studio Deen anime adaptation of Fate/stay night, he got one dialogue where Kiritsugu looked at the night sky and said "the moon is beautiful tonight" and then died with a sad laugh. However the staff were so touched that they made him do take after take of the line.
Koyama was glad to do it, but he wondered why they were so concerned about one line in a huge production. Later on he found out the line was a key point that started the entire story of Fate. He was very surprised when he heard that. Because he had been in that, he was able to play the part of Kiritsugu again in Fate/Zero. He had never thought that tiny part would lead to a development like this..[18]

Takeuchi's comment
Kiritsugu as a child. He looks like the protagonist of a shonen manga. [Takeuchi]

Comment for KiritsuguTakeuchi:Tentatively, the protagonist of Fate/Zero... but even so, in terms of artwork, his presence was small. The two times he appeared on the cover, one shot only showed him from the back, the other had him in silhouette.Urobuchi: Because he abstains from the flashiness of the Heroic Spirits. Rather, the best solution was to make him so unnoticeable. After all, a character who spreads justice should speak with their backs!Takeuchi:Despite being so shady, his first person pronoun is "boku", so it makes him sound rather moe.Urobuchi: That's the charm of Nasu's initial design. Urobuchi could not come up with that sort of self-address.

Norikata Emiya [Person's name]
Kiritsugu’s father. His family thaumaturgy involved time manipulation inside the body or possibly small cause-and-effect, and he was a genius who in only the fourth generation, a relatively shallow generation, rose to the rank of gaining a Sealing Designation.
Spent more than 20 years hiding from the pursuit of the Magic Association, and finally hid himself on a small southern island. Though Norikata’s wife died at the hands of the Magic Association’s hunters, Kiritsugu, who had just been born at the time, has no memory of the incident.
Accelerating or slowing the flow of time inside a Reality Marble free from the world’s interference is the thaumaturgy of the Emiya family. But after investigating it thoroughly, Norikata found that, in a Bounded Field that was minimized until resistance was almost zero, the flow of time could be accelerated without limit, and reaching the Root would be possible, right before observing the universe’s end. Although the theory itself was very promising, finishing the experiment would still require several hundreds of years. In order to resolve the issue of life span, he decided to explore the methods of becoming a Dead Apostle.
The tragedy that arose as a result was the story narrated at the beginning of Volume 4 of Zero.

Comment
Tomonori Sudo
Character Designs, Animation Director
At first, I thought that he (Kiritsugu) was a character who wasn't capable of expressing much emotion, but I think that in the latter half of the show, me might have managed to bring out the side of him that's rather frail and weak in comparison to his hard exterior. And since he's a character with the strength to blot that out, it's a difficult thing to do.

Kiritsugu Emiya
Saber's Master.
A freelance Mage-killer. Asked to marry into the Einzbern family, and then becomes their trump card in the Holy Grail War. He uses the magic of Innate Time Control to manipulate and alter the flow of time within his own body. As one would expect of an assassin who suppresses his emotions, his face is blank and his eyes are vacant. Tomonori Sudo was in charge of the character design for the anime version.

Maiya Hisau
Kiritsugu Emiya's partner. She met Kiritsugu on the battlefield, and has fought her entire life like a machine, considering herself a part whose function is to help Kiritsugu. She dresses entirely in black, and gives the cold, distant impression of someone who doesn't have a strong sense of self. Like Kiritsugu, she use a Steyr AUG and Calico M950 as weapons.

Kiritsugu Emiya (as a boy)
He spent his youth wandering around the world with his father, Norikata Emiya, who was on the run from the Mage's Association. At his point, he is still a dreamer of a boy who knows nothing of the world. His Shining eyes and tanned skin make him look cheerful. However, he comes face to face with harsh reality on Arimago Island.

Kiritsugu Emiya (as a young man)
Kiritsugu spent his days traveling around the world hunting down evil Mages. At first, he only got in Natalia's way, but he eventually becomes her partner and equal. However, living the life of a Mage-Killer forces him to confront a harsh reality.

Kiritsugu Emiya [Person's name]
The protagonist of Fate/Zero's prologue and epilogue, more or less.
He is the epitome of pragmatism, willing to do anything to achieve his goals. He is an idealist that dreams of world peace, but his method of attaining it is that of a cold and ruthless realist. He loves humanity, but he would not hesitate for a second to kill any single person. But though he lacks both hesitation and doubt, he cannot throw away his sadness.
Essentially, he's a magical 007, who treats sorcery as a mere tool and has no qualms using modern technology when it's more effective to do so. I really wanted to have him go on a rampage in a fully-loaded spy car, but I guess if you think about it Saber's V-Max sort of filled that role.
Though a young boy once looked up to him as a "superhero", he himself lost that admiration at an early stage, eventually coming to curse the very concept of justice itself. The only thing that kept him going was a desire that the sacrifices he had already made not be in vain. Thanks to this pessimistic attitude, his rank as a "superhero" is far inferior to the Heroic Spirit that shares his last name. Perhaps if he had a little more of the evil charisma of a last boss he would have been successful, but at the end of the day what he really wanted was just to pass away the days with his family in tranquil serenity.
Just like an eroge protagonist, he emitted a mysterious radiation that attracted women to him, but sadly everyone ensnared by it inevitably met a terrible end.
The only woman capable of smashing through this curse was the legendary Tiger of Fuyuki. Wow, Fuji-nee, you're so amazing!
If you count backwards from when he died, it turns out that his most active time on the battlefield was actually in his late teens. But hey, that's not so strange, you know.
Just look at Yagashira Dai or Sagara Sousuke. There are lots of heroes like that in this world.

Maiya Hisau [Person's name]
Assistant of Kiritsugu Emiya. Mistress - it is the word whether to define on her.
Because she spent her childhood in an environment deprived of humanity, Maiya, who lacks a sense of self, considers that her entire being belongs to Kiritsugu Emiya. Asking whether she loves Kiritsugu is like asking whether the innards love the brain. The question itself is meaningless.
Also, to Kiritsugu, allowing his wife to sacrifice herself and complete the Grail is a betrayal towards her love, no matter what others say. However, it is necessary that he does not hesitate in this betrayal. To Kiritsugu, his sexual relationship with Maiya is a rehearsal before this betrayal, a form of self-abuse to steel his nerves while walking down this path. This is probably the sorriest excuse to have an affair, but Maiya deemed it okay. It is essentially a negative spiral downward without an end.
In terms of skills in magcraft, Maiya is only slightly better than Kokutou Azaka. However, she is a professional killer who can wield even the crudest weapons to deadly effect. In this sense, she is enough to be called a user of 'deadly magecraft'.

Kiritsugu Emiya [Person's name]
Freelance magus.
He passed away at the age of 34.
For better or for worse, he was the one decided Shirou's way of life.
Kiritsugu was Shirou's foster father.
The Master of Saber during the previous Holy Grail War, and he emerged victorious at the end.
He favoured guns, and practiced a special magecraft called Innate Time Control.
His aptitude as a Master was unremarkable, but he was an adept when it came to "slaying the opposing magi".
In a way, he was the hitman of the Mages' Association. Because of this reputation, he earned the contract and favour of the Einzberns.
During the Holy Grail War, he deceived an opposing Master, held his lover as hostage, and detonated a building. He was a villain not unlike the young Kotomine. ... Really, Kotomine was also quite young at that time.
Maybe it was the fate of gentle man, Kiritsugu naturally had wife and lover.
When not working as a magus, he was extremely chivalrous. He told little Shirou that "boys who make a girl cry will end in ruins".
...Hmm? Was this guy really a feminist?
After the Holy Grail War, he passed away from the corruption of "All the World's Evil" due to Kotomine.

Shirley [Person's name]
A native of Alimango Island, where Emiya Norikata chose to sequester himself away from the outside world. Though the educational environment she grew up in was extremely poor – she did not even attend elementary school, and only learned reading and writing from the local priest – it was enough to stimulate her ample intellectual curiosity, and by the time she was 13 years old she had already received a master's degree through correspondence courses alone. Of course, this talent did not go unnoticed by Emiya Norikata. He brought her on as his assistant, putting her in charge of handling all the miscellaneous daily tasks in the Emiya household.
While she did receive some training from Norikata, it was not at the level of being taken on as his disciple. He simply taught her the basics of the basics, and nothing more. And really, even calling it that much is a stretch. All he actually did was interact with her without bothering to hide his true nature as a magus. Nevertheless, Shirley's innate thirst for knowledge allowed her to absorb Norikata's words at an astonishing pace, and he expected great things from her in the future. However, as the old saying goes, "Curiosity killed the cat." In the end, her inquisitive mind brought about a tragedy.
She was the young Kiritsugu's very first love. It seems that the reason he ended up pampering the kendo girl he met in his later years so much was because she reminded him so much of Shirley.

[v] Game Japan 2007-02 issue - How high (or low) are the talents of Emiya Shirou and Tohsaka Rin within the entire history of the Association?

GJ: I have a question about Fate characters. How high (or low) are the talents of Emiya Shirou and Tohsaka Rin within the entire history of the Association?Nasu: Rin really is a genius. Given time, she'll enter within the top 100 magi of the Association throughout its entire history. Shirou won't move out from being an magus apprentice, but as a spell-user, he'll be among one of the big specialists. Ultimately, he'll receive an evaluation on the same level as "Magus Killer" Emiya Kiritsugu had in his peak, maybe. If I were to put into simple numbers, Ciel: 100, Rin: 70-100, Shirou: 10 (under particular limited conditions, then 40).

Calico M950 [Armament]
One of the weapons Emiya Kiritsugu prepared for the Holy Grail War. You didn't really think he'd enter something like a survival game with just a sniper rifle and the Contender, did you?
The distinguishing feature of the Calico is its special top-mounted helical magazine that can hold 50 rounds, but no matter how much I think about it the extra weight and change in the center of gravity while firing means it would be better to use a normal submachine gun, even if you have to reload more often. But oh, well, Kiritsugu is a magical mystery gunman, so I guess it's fine.
Of course, in the final battle when he used it to pin down Kirei, he was able to buy himself five seconds where a normal submachine gun only would have gotten three. That extra two second advantage is a testament to the superiority of the helical magazine! …Okay, so it's not that much of a difference.
By the way, my intention was to make Kiritsugu as much of a heretical gunman as he is a heretical magus, so I purposefully chose his equipment based on coolness factor rather than practicality. Please, please, please don't think that the weapons that show up in Fate/Zero are the standard for actual professional soldiers.

Thompson Center Arms Contender Custom [Armament]
The customized firearm that Emiya Kiritsugu uses as a mystic code. It is a single-shot pistol originally developed for use in hunting and competitions. The barrel can be easily switched out, allowing it to be used with a large variety of bullet calibers. By fitting it with a handmade barrel forged using magical processes, and using special bullets that contain his own powdered ribs, Kiritsugu has transformed it into a deadly anti-magus weapon. Well, that's the short version; for a significantly more long winded explanation please refer to volume 2.
Incidentally, this gun was actually what made me want to write a story like Fate/Zero in the first place. In a way, you could say it was the start of everything. Or more specifically, it was Lance Henriksen's performance in Hard Target. I guess what I'm trying to say is, thank you so much, Mr. John Woo. Stranglehold was really fun. Will there be flying doves in Red Wall, too?

Nasu: To use an RPG analogy, the Origin Round is like an attack that converts the opponent's MP into damage. For example, Kayneth with his 3000 MP would receive 3000 damage against his mere 100 HP. For someone like Waver with 5 MP, he would only receive 5 damage against his 50 HP.

Walther WA2000 [Armament]
The sniper rifle used by Emiya Kiritsugu in the Holy Grail War. Despite being relatively compact due to its bullpup design, it is an extremely heavy and hard to use weapon. On top of that, Kiritsugu's is decked out with a preposterous night vision system. The night vision scopes that existed during the time period of the Fourth Holy Grail War were a long way off from where they are today, and were often bulkier and heavier than the guns they were attached to. Also, one of the gun's major flaws was its prohibitive cost, which is one of the reasons it never saw widespread use, but thanks to the Einzbern's considerable funds that was no problem at all. And besides, it was probably less expensive than running telephone lines all the way out to a castle in the middle of nowhere.